Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 7, 2019; 25(29): 3838-3841
Published online Aug 7, 2019. doi: 10.3748/wjg.v25.i29.3838
Healthy axis: Towards an integrated view of the gut-brain health
Federico Boem, Amedeo Amedei
Federico Boem, Department of Oncology and Hemato-Oncology, University of Milan, Milano 20122, Italy
Amedeo Amedei, Department of Experimental and Clinical Medicine, University of Florence, Firenze 50134, Italy
Amedeo Amedei, Department of Biomedicine, Azienda Ospedaliera Universitaria Careggi, Firenze 50134, Italy
Author contributions: Boem F conceived the study and wrote the manuscript; Amedei A conceived the study and drafted the manuscript. Both authors approved the final version of the article.
Conflict-of-interest statement: The authors have no conflict of interest to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Amedeo Amedei, BSc, Associate Professor, Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 03, Firenze 50134, Italy. amedeo.amedei@unifi.it
Telephone: +39-55-2758330 Fax: +39-55-2758330
Received: May 7, 2019
Peer-review started: May 7, 2019
First decision: June 9, 2019
Revised: June 14, 2019
Accepted: June 22, 2019
Article in press: June 23, 2019
Published online: August 7, 2019

Despite the lack of precise mechanisms of action, a growing number of studies suggests that gut microbiota is involved in a great number of physiological functions of the human organism. In fact, the composition and the relations of intestinal microbial populations play a role, either directly or indirectly, to both the onset and development of various pathologies. In particular, the gastrointestinal tract and nervous system are closely connected by the so-called gut–brain axis, a complex bidirectional system in which the central and enteric nervous system interact with each other, also engaging endocrine, immune and neuronal circuits. This allows us to put forward new working hypotheses on the origin of some multifactorial diseases: from eating to neuropsychiatric disorders (such as autism spectrum disorders and depression) up to diabetes and tumors (such as colorectal cancer). This scenario reinforces the idea that the microbiota and its composition represent a factor, which is no longer negligible, not only in preserving what we call “health” but also in defining and thus determining it. Therefore, we propose to consider the gut-brain axis as the focus of new scientific and clinical investigation as long as the locus of possible systemic therapeutic interventions.

Keywords: Microbiota, Gut-brain axis, Dysbiosis, Symbiosis, Person-centered medicine, Personalized medicine

Core tip: The interest for gut-microbiota is rapidly increasing due to its impact on many physiological and pathological functions. In particular, gut-brain axis, in which commensal microorganisms’ impact, in interplay with immune and endocrine systems, might be a tool and a focus of both scientific investigation and therapeutic interventions. Accordingly, here, by focusing on some examples of multifactorial conditions, such as obesity, we advocate for a redefined health account, in eco-systemic terms, in order to promote a new way of considering the detection of and the approach to diseases. A healthy axis could become part of a more effective perspective towards both person-centered medicine and personalized medicine.